Minecraft snapshot 14w05a released

It's that time again -- a new Minecraft snapshot has been released. So what's new this week? As per usual, Nathan "Dinnerbone" Adams has provided a nice concise list of changes contained in snapshot 14w05a:

Notable additions for survival:

Book copying mechanics has been altered to differentiate the original & copies of books

Activator rails can eject entities from Minecarts

Notable additions for mapmakers:

Added a spectator gamemode (/gamemode spectator). Not 100% finished.

Spectators cannot be seen by anybody but other spectators

Spectators can view inventories/etc, but not modify them

Spectators can go through any entity or block without interfering with it

Spectators can click on entities to take their camera

Spectators cannot use items, place blocks, destroy blocks or interact with blocks in any way